Hi,
I have been working on Zephyr for the past weeks and have been able to set multiple GPIOs, interrupts and RF functionnalities. But so far, I thought I could handle the PWMs well, until today. I found out every time I try to set PWM outputs to other pins than the default ones, nothing happened.
To be precise, if I put my LEDs on the default output of the nRF52840 demoboard everything is fine. But nothing happen on any other outputs.
To set things up, I write this fragment of overlay :
/ {
pwmleds {
pwm_led_0 {
pwms = <&pwm0 17>;
status = "okay";
};
pwm_led1: pwm_led1 {
pwms = <&pwm0 19>;
status = "okay";
};
pwm_led2: pwm_led2 {
pwms = <&pwm0 21>;
status = "okay";
};
pwm_led3: pwm_led3 {
pwms = <&pwm0 23>;
status = "okay";
};
};
aliases {
pwm-led0 = &pwm_led0;
pwm-led1 = &pwm_led1;
pwm-led2 = &pwm_led2;
pwm-led3 = &pwm_led3;
};
};
&pwm0 {
status = "okay";
ch0-pin = <17>;
ch0-inverted;
ch1-pin = <19>;
ch1-inverted;
ch2-pin = <21>;
ch2-inverted;
ch3-pin = <23>;
ch3-inverted;
};
Then the PWMs are set up in the main.c like this :
#define PWM_LED0_NODE DT_ALIAS(pwm_led0)
#define PWM_LED1_NODE DT_ALIAS(pwm_led1)
#define PWM_LED2_NODE DT_ALIAS(pwm_led2)
#define PWM_LED3_NODE DT_ALIAS(pwm_led3)
#if DT_NODE_HAS_STATUS(PWM_LED0_NODE, okay)
#define PWM0_CTLR DT_PWMS_CTLR(PWM_LED0_NODE)
#define PWM0_CHANNEL DT_PWMS_CHANNEL(PWM_LED0_NODE)
#define PWM0_FLAGS DT_PWMS_FLAGS(PWM_LED0_NODE)
#else
#error "Unsupported board: pwm-led0 devicetree alias is not defined"
#define PWM0_CTLR DT_INVALID_NODE
#define PWM0_CHANNEL 0
#define PWM0_FLAGS 0
#endif
#if DT_NODE_HAS_STATUS(PWM_LED1_NODE, okay)
#define PWM1_CTLR DT_PWMS_CTLR(PWM_LED1_NODE)
#define PWM1_CHANNEL DT_PWMS_CHANNEL(PWM_LED1_NODE)
#define PWM1_FLAGS DT_PWMS_FLAGS(PWM_LED1_NODE)
#else
#error "Unsupported board: pwm-led1 devicetree alias is not defined"
#define PWM1_CTLR DT_INVALID_NODE
#define PWM1_CHANNEL 0
#define PWM1_FLAGS 0
#endif
#if DT_NODE_HAS_STATUS(PWM_LED2_NODE, okay)
#define PWM2_CTLR DT_PWMS_CTLR(PWM_LED2_NODE)
#define PWM2_CHANNEL DT_PWMS_CHANNEL(PWM_LED2_NODE)
#define PWM2_FLAGS DT_PWMS_FLAGS(PWM_LED2_NODE)
#else
#error "Unsupported board: pwm-led2 devicetree alias is not defined"
#define PWM2_CTLR DT_INVALID_NODE
#define PWM2_CHANNEL 0
#define PWM2_FLAGS 0
#endif
#if DT_NODE_HAS_STATUS(PWM_LED3_NODE, okay)
#define PWM3_CTLR DT_PWMS_CTLR(PWM_LED3_NODE)
#define PWM3_CHANNEL DT_PWMS_CHANNEL(PWM_LED3_NODE)
#define PWM3_FLAGS DT_PWMS_FLAGS(PWM_LED3_NODE)
#else
#error "Unsupported board: pwm-led2 devicetree alias is not defined"
#define PWM3_CTLR DT_INVALID_NODE
#define PWM3_CHANNEL 0
#define PWM3_FLAGS 0
#endif
uint32_t max_period = 255*100;
pwm_red = 255*100;
pwm_green = 255*100;
pwm_blue = 255*100;
void init()
{
int ret;
ret = pwm_pin_set_usec(pwm0, PWM0_CHANNEL, max_period, pwm_red, PWM0_FLAGS);
if (ret) {
printk("Error %d: failed to set pulse width\n", ret);
return;
}
ret = pwm_pin_set_usec(pwm1, PWM1_CHANNEL, max_period, pwm_green, PWM1_FLAGS);
if (ret) {
printk("Error %d: failed to set pulse width\n", ret);
return;
}
ret = pwm_pin_set_usec(pwm2, PWM2_CHANNEL, max_period, pwm_blue, PWM2_FLAGS);
if (ret) {
printk("Error %d: failed to set pulse width\n", ret);
return;
}
ret = pwm_pin_set_usec(pwm3, PWM3_CHANNEL, max_period, pwm_white, PWM3_FLAGS);
if (ret) {
printk("Error %d: failed to set pulse width\n", ret);
return;
}
}
I may add that the output pins are indeed changing as the default ones are not working anymore with this configuration.
Best regards,
Charles
